In some cases of catheter therapy, a user causes an X-ray fluoroscopic image based on X-ray imaging by an X-ray diagnostic apparatus to be displayed in real time, and performs a procedure while recognizing the position of a catheter in the X-ray fluoroscopic image.
Techniques for assisting the procedure of a user for catheter therapy include a technique that displays a real-time X-ray fluoroscopic image overlaid with an image of blood vessels stained with a contrast medium, a white blank image of this image, a three-dimensional vascular image or the like as a catheter road map image. This type of techniques allow the position of a catheter appearing in a real-time X-ray fluoroscopic image, and a road map image displaying the flowing direction of bloodstream at the same site to be recognized at the same time. This facilitates the user's grasping the catheter advancing direction even when the site has a complicated structure, and allows a correct catheter operation.
Unfortunately, in the case of using an image of blood vessels stained with a contrast medium or a white blank image of this image as a road map image, it is difficult to discriminate whether a portion where a blood vessel appears branched is actual branching of the identical blood vessel or an intersection between different blood vessels located at the front and rear in the depth direction of the image. On the other hand, in the case of using a three-dimensional vascular image as a road map image, it is easy to discriminate between branching of the identical blood vessel and an intersection of blood vessels, but great efforts and time are required to prepare the three-dimensional vascular image as the road map image, in the first place. Alignment between a prepared three-dimensional vascular image and a real-time X-ray fluoroscopic image is significantly difficult. The images often deviate from each other. The positional deviation makes the procedure of the user difficult.
The present invention has an object to provide an image processing apparatus, an X-ray diagnostic apparatus, and an image processing method capable of displaying an image facilitating discrimination between branching of the identical blood vessel and an intersection of blood vessels.